The present invention relates to a wheel brake, and particularly to an overrunning wheel brake.
Overrunning wheel brakes are known, which have two brake shoes, a support provided with at least one guiding cam, guiding roller and the like and supporting one of the brake shoes which is operative to be pressed against a brake drum during movement in forward direction, and a tightening member acting in the operative direction of the first brake shoe and pressing the support member toward the brake drum. The second brake shoe abuts against the support member. The first brake shoe is provided, in the region of the guiding cam, guiding roller and the like of the support, with lifting tracks which, together with the outer curved wall of the brake shoe, form wedging faces converging in the operative direction of the first brake shoe. The second brake shoe abuts during the forward movement against a stationary abutment member.
The provision in the above-mentioned wheel brake of the lifting tracks on the first brake shoe and the abutment of these lifting tracks against the guiding cams, guiding rollers or the like of the support member provide for enormous braking force in forward direction, inasmuch as the first brake shoe is substantially wedged against the brake drum via the above-mentioned lifting tracks. However, this action does not take place during reverse movement.